Exegesis:

kai apokritheis eipen autois ‘and answering he said to them.’ apokritheis implies that the story about the killing had intimated some question or statement about the sinfulness of the people who had been killed.

dokeite hoti hoi Galilaioi houtoi hamartōloi para pantas tous Galilaious egenonto ‘do you think that these Galileans were sinners, more than all (other) Galileans,’ i.e. greater sinners than all other Galileans. For dokeō cf. on 8.18. For hamartōlos cf. on 5.8. For para with accusative meaning ‘beyond,’ ‘more than.’ egenonto is equivalent to the (non-existing) aorist of eimi.

hoti tauta peponthasin ‘because they suffered these things.’ tauta is pronominal accusative of content. The perfect tense refers to an event which was irrevocable.

Translation:

Do you think, see 12.51.

Were worse sinners than …, or, ‘were more sinful than…,’ ‘sinned more (gravely) than….’

Because they suffered thus gives the reason of what Jesus understands the people to be thinking. To bring this out it is sometimes sufficient to place the phrase nearer to ‘do you think’ (cf. An American Translation, The Four Gospels – a New Translation), but often further adjustment is required, e.g. ‘is it because these men suffered thus that you think they are worse…,’ ‘do you think: that these men suffered thus (or, what these men suffered) proves that (or, is because) they are worse….’ The verb to suffer here means, ‘to experience (or, to be subjected to) something bad,’ ‘have something bad happen to one,’ hence, “because this happened to them” (An American Translation); the thing suffered was death, cf. “because these G. were killed” (Good News Translation), ‘their death’ (Tae’ 1933).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.